Mr Thompson told reporters on Wednesday that the materials obtained by his committee were a combination of different communications including “text messages, radio traffic ... thousands of exhibits”, as Axios reported.
The receipt of “thousands” of materials comes three months after the committee issued a subpoena for Secret Service communications from the day of the assault on the US Capitol and the day before.
It remains unclear what, if any, new information has been obtained by the panel, which has recently announced a second round of hearings for September.
“We’ve got a number of staffers going through it all right now,” said Mr Thompson in comments reported by Bloomberg. “It’s a work in progress.”
In July, two sources familiar with the investigation told Guardian that the Secret Service had provided only one text message in response to the subpoena regarding January 6 after it emerged that many messages had been lost or deleted.
A spokesperson for the agency had said the deletion of messages was the result of a “pre-planned, three-month system migration” and a “device replacement program”, reports previously said.
Zoe Lofgren, another Democrat member of Congress on the January 6 committee, told MSNBC on Wednesday that they were now going through the materials and that “more is coming in”.
“There’s texts, there’s emails, there’s radio traffic, there’s all kinds of information. [Microsoft] Teams meetings,” she said. “We’re going through everything that’s been provided. More is coming in.”
Secret Service agents – who provide personal security and protection for US presidents – have been cited multiple times by those who have testified in front of the January 6 committee earlier this year.
That included claims that Donald Trump, the former president, tried to grab the wheel of the presidential limousine and lunged at a Secret Service agent on the day of the Capitol riot.
Secret Service agents were also tasked with helping transfer then-vice president Mike Pence to a secure location as a pro-Trump mob breached the Capitol in an apparent effort to overturn the 2020 US election.